1 # pthread_sigmask.m4 serial 18
2 dnl Copyright (C) 2011-2020 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 AC_DEFUN([gl_FUNC_PTHREAD_SIGMASK],
9 AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
11 AC_CHECK_FUNCS_ONCE([pthread_sigmask])
13 dnl On MinGW pthread_sigmask is just a macro which always returns 0.
14 dnl It does not exist as a real function, which is required by POSIX.
15 AC_CACHE_CHECK([whether pthread_sigmask is a macro],
16 [gl_cv_func_pthread_sigmask_macro],
17 [AC_EGREP_CPP([headers_define_pthread_sigmask], [
20 #ifdef pthread_sigmask
21 headers_define_pthread_sigmask
23 [gl_cv_func_pthread_sigmask_macro=yes],
24 [gl_cv_func_pthread_sigmask_macro=no])
29 if test $gl_cv_func_pthread_sigmask_macro = yes; then
30 dnl pthread_sigmask is a dummy macro.
31 HAVE_PTHREAD_SIGMASK=0
32 dnl Make sure to '#undef pthread_sigmask' before defining it.
33 REPLACE_PTHREAD_SIGMASK=1
35 dnl Test whether the gnulib module 'threadlib' is in use.
36 dnl Some packages like Emacs use --avoid=threadlib.
37 dnl Write the symbol in such a way that it does not cause 'aclocal' to pick
38 dnl the threadlib.m4 file that is installed in $PREFIX/share/aclocal/.
39 m4_ifdef([gl_][THREADLIB], [
40 AC_REQUIRE([gl_][THREADLIB])
42 if test "$gl_threads_api" = posix; then
43 if test $ac_cv_func_pthread_sigmask = yes; then
44 dnl pthread_sigmask is available without -lpthread.
47 if test -n "$LIBMULTITHREAD"; then
48 AC_CACHE_CHECK([for pthread_sigmask in $LIBMULTITHREAD],
49 [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD],
51 LIBS="$LIBS $LIBMULTITHREAD"
54 [[#include <pthread.h>
57 [[return pthread_sigmask (0, (sigset_t *) 0, (sigset_t *) 0);]])
59 [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=yes],
60 [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=no])
63 if test $gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD = yes; then
64 dnl pthread_sigmask is available with -pthread or -lpthread.
65 LIB_PTHREAD_SIGMASK="$LIBMULTITHREAD"
67 dnl pthread_sigmask is not available at all.
68 HAVE_PTHREAD_SIGMASK=0
71 dnl pthread_sigmask is not available at all.
72 HAVE_PTHREAD_SIGMASK=0
76 dnl pthread_sigmask may exist but does not interoperate with the chosen
77 dnl multithreading facility.
78 if test $ac_cv_func_pthread_sigmask = yes; then
79 REPLACE_PTHREAD_SIGMASK=1
81 HAVE_PTHREAD_SIGMASK=0
85 dnl The module 'threadlib' is not in use, due to --avoid=threadlib being
87 dnl The package either has prepared CPPFLAGS and LIBS for use of
88 dnl POSIX:2008 threads, or wants to build single-threaded programs.
89 if test $ac_cv_func_pthread_sigmask = yes; then
90 dnl pthread_sigmask exists and does not require extra libraries.
91 dnl Assume that it is declared.
94 dnl pthread_sigmask either does not exist or needs extra libraries.
95 HAVE_PTHREAD_SIGMASK=0
96 dnl Define the symbol rpl_pthread_sigmask, not pthread_sigmask,
97 dnl so as to not accidentally override the system's pthread_sigmask
98 dnl symbol from libpthread. This is necessary on IRIX 6.5.
99 REPLACE_PTHREAD_SIGMASK=1
104 AC_SUBST([LIB_PTHREAD_SIGMASK])
105 dnl We don't need a variable LTLIB_PTHREAD_SIGMASK, because when
106 dnl "$gl_threads_api" = posix, $LTLIBMULTITHREAD and $LIBMULTITHREAD are the
109 dnl Now test for some bugs in the system function.
110 if test $HAVE_PTHREAD_SIGMASK = 1; then
111 AC_REQUIRE([AC_PROG_CC])
112 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
114 dnl On FreeBSD 6.4, HP-UX 11.31, Solaris 9, in programs that are not linked
115 dnl with -lpthread, the pthread_sigmask() function always returns 0 and has
117 if test -z "$LIB_PTHREAD_SIGMASK"; then
122 AC_CACHE_CHECK([whether pthread_sigmask works without -lpthread],
123 [gl_cv_func_pthread_sigmask_in_libc_works],
134 return pthread_sigmask (1729, &set, NULL) != 0;
136 [gl_cv_func_pthread_sigmask_in_libc_works=no],
137 [gl_cv_func_pthread_sigmask_in_libc_works=yes],
141 freebsd* | hpux* | solaris | solaris2.[2-9]*)
142 gl_cv_func_pthread_sigmask_in_libc_works="guessing no";;
144 gl_cv_func_pthread_sigmask_in_libc_works="guessing yes";;
149 case "$gl_cv_func_pthread_sigmask_in_libc_works" in
151 REPLACE_PTHREAD_SIGMASK=1
152 AC_DEFINE([PTHREAD_SIGMASK_INEFFECTIVE], [1],
153 [Define to 1 if pthread_sigmask may return 0 and have no effect.])
159 dnl On Cygwin 1.7.5, the pthread_sigmask() has a wrong return value
160 dnl convention: Upon failure, it returns -1 and sets errno.
161 AC_CACHE_CHECK([whether pthread_sigmask returns error numbers],
162 [gl_cv_func_pthread_sigmask_return_works],
165 LIBS="$LIBS $LIB_PTHREAD_SIGMASK"
175 if (pthread_sigmask (1729, &set, NULL) == -1)
179 [gl_cv_func_pthread_sigmask_return_works=yes],
180 [gl_cv_func_pthread_sigmask_return_works=no],
183 gl_cv_func_pthread_sigmask_return_works="guessing no";;
185 gl_cv_func_pthread_sigmask_return_works="guessing yes";;
190 case "$gl_cv_func_pthread_sigmask_return_works" in
192 REPLACE_PTHREAD_SIGMASK=1
193 AC_DEFINE([PTHREAD_SIGMASK_FAILS_WITH_ERRNO], [1],
194 [Define to 1 if pthread_sigmask(), when it fails, returns -1 and sets errno.])
198 dnl On IRIX 6.5, in a single-threaded program, pending signals are not
199 dnl immediately delivered when they are unblocked through pthread_sigmask,
200 dnl only a little while later.
201 AC_CACHE_CHECK([whether pthread_sigmask unblocks signals correctly],
202 [gl_cv_func_pthread_sigmask_unblock_works],
206 gl_cv_func_pthread_sigmask_unblock_works="guessing no";;
208 gl_cv_func_pthread_sigmask_unblock_works="guessing yes";;
210 m4_ifdef([gl_][THREADLIB],
211 [dnl Link against $LIBMULTITHREAD, not only $LIB_PTHREAD_SIGMASK.
212 dnl Otherwise we get a false positive on those platforms where
213 dnl $gl_cv_func_pthread_sigmask_in_libc_works is "no".
215 LIBS="$LIBS $LIBMULTITHREAD"])
223 static volatile int sigint_occurred;
225 sigint_handler (int sig)
234 signal (SIGINT, sigint_handler);
236 sigaddset (&set, SIGINT);
237 if (!(pthread_sigmask (SIG_BLOCK, &set, NULL) == 0))
239 sprintf (command, "sh -c 'sleep 1; kill -%d %d' &", SIGINT, pid);
240 if (!(system (command) == 0))
243 if (!(sigint_occurred == 0))
245 if (!(pthread_sigmask (SIG_UNBLOCK, &set, NULL) == 0))
247 if (!(sigint_occurred == 1)) /* This fails on IRIX. */
252 [gl_cv_func_pthread_sigmask_unblock_works=no],
254 m4_ifdef([gl_][THREADLIB], [LIBS=$gl_save_LIBS])
256 case "$gl_cv_func_pthread_sigmask_unblock_works" in
258 REPLACE_PTHREAD_SIGMASK=1
259 AC_DEFINE([PTHREAD_SIGMASK_UNBLOCK_BUG], [1],
260 [Define to 1 if pthread_sigmask() unblocks signals incorrectly.])
266 # Prerequisite of lib/pthread_sigmask.c.
267 AC_DEFUN([gl_PREREQ_PTHREAD_SIGMASK],
269 if test $HAVE_PTHREAD_SIGMASK = 1; then
270 AC_DEFINE([HAVE_PTHREAD_SIGMASK], [1],
271 [Define to 1 if the pthread_sigmask function can be used (despite bugs).])